Journal of Rangeland Science (JRS) Investigation of Changes in Rangeland Vegetation Regarding Different Slopes, Elevation and Geographical Aspects (Case Study: Yazi Rangeland, Noor County, Iran) Volume 4 (2014) Issue 3, July 2014 2024 01 30 Investigation of Changes in Rangeland Vegetation Regarding Different Slopes, Elevation and Geographical Aspects (Case Study: Yazi Rangeland, Noor County, Iran) EN Hamid Reza Saeedi Goraghani Range Management, Department of Reclamation of Arid and Mountainous Regions, University of Tehran Mojtaba Solaimani Sardo Combat Desertification, Faculty of Natural Resources and Earth Science, University of Kashan Nabi Azizi Forestry, University of Tehran Ali Azareh Assistant Professor, Department of Geography, Faculty of Literature and Humanities, University of Jiroft, Kerman, Iran. Sara Heshmati Range Management, Agricultural Science and Natural Resources University of Sari Journal Article 2024 01 30 In many studies, topographic factors have been considered as an important factor in establishing the vegetation in different ecosystems. So, it affects vegetation composition and diversity by influencing soil moisture, fertility and soil depth. The aim of this research was to investigate the effects of slope, elevation and geographical aspects on species growth, forage production and vegetation cover in Yazi rangeland, Noor province, Iran. Sampling was done along three transects with the length of 150 m in each unit. Along each transect, 15 plots (1 m2) were established with 10 m distances. In each plot, species name, growth form, cover percent and soil surface percent such as percentages of stones, pebbles and amount of litter were recorded. Also, the rangeland production was measured by the clip-and-weigh method. Data were analyzed and mean comparisons were done using Duncan method. Results showed that the geographical aspects had significant impacts on forage production, vegetative form and species composition. Northern aspects had the highest forage production rate and species frequency. Also, elevation had a significant effect on forage production and vegetative form so that the elevation of 1600-1900 m and 2200-2500 m had the highest and lowest effects. Also, according to forage production and vegetative form in the range of slope classes, it is specified that it has also a significant effect on forage production seen in higher slopes.